1845 February: William dies; Wallace leaves Collegiate School and takes over his business

1848 25 April: Wallace and Bates leave England for Amazonian South America to begin a natural history collecting expedition (for a full chronology of Wallace's activities over the next four years, see George 1964)

1852 12 July: Leaves South America for return to England; on 6 August his ship burns and sinks and ten days later he is rescued at sea

1852 1 October to March 1854: primarily London-based; in 1853 publishes Palm Trees of the Amazon and A Narrative of Travels on the Amazon and Rio Negro

1854 March 1: Leaves England for the Far East to begin a natural history collecting expedition

1854 20 April to 20 February 1862: Collecting expedition in the Malay Archipelago (for a full chronology of Wallace's activities during this period, see Bastin 1986)

1855 February: While in Sarawak writes 'On the Law Which Has Regulated the Introduction of New Species' for publication

1858 February: Writes 'On the Tendency of Varieties to Depart Indefinitely From the Original Type' and sends it off to Charles Darwin for comment

1858 1 July: Wallace's and Darwin's writings on natural selection are presented at a meeting of the Linnean Society

1859 November: 'On the Zoological Geography of the Malay Archipelago,' the paper describing Wallace's Line, is read before the Linnean Society; Darwin's On the Origin of Species is published

1862 1 April: Returns to English soil

1864 1 March: Presents 'The Origin of Human Races Deduced From the Theory of "Natural Selection"' to the Anthropological Society of London